What version of XP are you using? SP0, SP1, SP2 or SP3? If I remember SP0 can only use 137GB. You have 2 options in that case.
First. Make a small partion. Say 100GB. Install XP. Install service packs. Use partitioning software to change the size.
Second. Download SP3 and slipstream it into your XP install disc. Here is a site that can help you do it. http://filesharingtalk.com/vb3/f-guides-and-tutorials-65/t-software-integrate-software-into-your-win-install-cd-161875
You can put your SATA and network drivers in too.